From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B88D2C79F82 for ; Tue, 8 Sep 2026 15:54:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=GD9uqjMFzVAwI3HFLeQg05MCFM41kAwYmShtqMqbL/g=; b=uKG/Hel0id9OD60RLo1pQgNzRm 2pcPQCHjHMEVHLzxIFDDrVIdGSDvHC5LlT+ntN1TnrvdGAYabUCx+oyixjwz7AqjWF58XEPaIFlm1 srJWeOxZbAgLLI2ubybIhQDuJNeCqBWGWsb9GHAiJ87Jt6SpTMK9Q2QdCgvcoioBP3+Pl4qUu+28f WmnjreIoKDmjjOUkm5aVmssxGCnvP5hgEnXnnWckbq/jZTQe8ZI0mPu1MfO+VJZ7r+jePTm3MYgEh KCvehM3b8HvMRXH/hK6jiLd7sKEMbc7k7UhfY/ykgPNY4hCzBuOMneJFQnad7XUZIt8g2FuJNa/bP dNrXVXqA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3y9S-00000009YqZ-1RBf; Tue, 08 Sep 2026 15:54:26 +0000 Received: from extorris.mess.org ([92.243.27.206]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x3y9Q-00000009YpD-04By; Tue, 08 Sep 2026 15:54:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1788882859; bh=544WQVZJeLYU7v3G3MGtP5wW/6wUd4jsHuoiTAyywkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xg8CIWyRctIvMnvVyP9XewMQybVqg7b0YVC9pBXSJDIIXjbCJM57nZV6iaz+upguk YNWyb1p62KeV1qLiCNAOaChsiNQs3xICig85+PgOlWRKuJfp5NN9EOqtV3pmHbt2Eq S0ohvTyhnl9tftVoH/ksQ8FoYY5jp/dHHlHX5nKslIxjffz56vzT2KI4Juniw8UN6Q JdA+183T5aKi/XOpf2SNaboyUIZYorzzfux1cwHpb3A8v6KMqHBpep2Ig1+4Hz7SDs irF3+nAxs/ccSIYQ4TumXsjc/bkariwqAHjTBcTl7TxtrZrAfsi/EY/UTnf1LJ5PKe Mw9rvycksrMgw== Received: by extorris.mess.org (Postfix, from userid 1004) id B8B1141473; Tue, 08 Sep 2026 16:54:19 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1788882859; bh=544WQVZJeLYU7v3G3MGtP5wW/6wUd4jsHuoiTAyywkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xg8CIWyRctIvMnvVyP9XewMQybVqg7b0YVC9pBXSJDIIXjbCJM57nZV6iaz+upguk YNWyb1p62KeV1qLiCNAOaChsiNQs3xICig85+PgOlWRKuJfp5NN9EOqtV3pmHbt2Eq S0ohvTyhnl9tftVoH/ksQ8FoYY5jp/dHHlHX5nKslIxjffz56vzT2KI4Juniw8UN6Q JdA+183T5aKi/XOpf2SNaboyUIZYorzzfux1cwHpb3A8v6KMqHBpep2Ig1+4Hz7SDs irF3+nAxs/ccSIYQ4TumXsjc/bkariwqAHjTBcTl7TxtrZrAfsi/EY/UTnf1LJ5PKe Mw9rvycksrMgw== Received: from maru.home (host86-150-50-53.range86-150.btcentralplus.com [86.150.50.53]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by extorris.mess.org (Postfix) with ESMTPSA id 0EAE141448; Tue, 08 Sep 2026 16:54:19 +0100 (BST) From: Sean Young To: linux-media@vger.kernel.org, Sean Young , Mauro Carvalho Chehab , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , Viktor Prutyanov Cc: Rik van Riel , stable@vger.kernel.org, Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 19/19] media: meson-ir-tx: Validate carrier and duty_cycle Date: Tue, 8 Sep 2026 16:52:07 +0100 Message-ID: <528055c59611d6711e15b05c5ab150d4d3d338af.1788882189.git.sean@mess.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260908_085424_205035_CB8307A2 X-CRM114-Status: GOOD ( 17.45 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org It is possible to set a combination of carrier and duty cycle that do not produce a correct signal. In addition, setting a carrier larger than USEC_PER_SEC will result in a divide by zero in meson_irtx_prepare_pulse() during transmit. Fixes: 49be1c78d575 ("media: rc: introduce Meson IR TX driver") Signed-off-by: Sean Young Cc: stable@vger.kernel.org --- drivers/media/rc/meson-ir-tx.c | 54 +++++++++++++++++++++++++++------- 1 file changed, 44 insertions(+), 10 deletions(-) diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c index 1ab898069e67..a410464ede22 100644 --- a/drivers/media/rc/meson-ir-tx.c +++ b/drivers/media/rc/meson-ir-tx.c @@ -76,11 +76,24 @@ struct meson_irtx { unsigned long clk_rate; }; -static void meson_irtx_set_mod(struct meson_irtx *ir) +static bool meson_irtx_calc_mod(unsigned long clk_rate, u32 carrier, + u32 duty_cycle, unsigned int *pulse_cnt, + unsigned int *space_cnt) { - unsigned int cnt = DIV_ROUND_CLOSEST(ir->clk_rate, ir->carrier); - unsigned int pulse_cnt = DIV_ROUND_CLOSEST(cnt * ir->duty_cycle, 100); - unsigned int space_cnt = cnt - pulse_cnt; + unsigned int cnt; + + cnt = DIV_ROUND_CLOSEST(clk_rate, carrier); + *pulse_cnt = DIV_ROUND_CLOSEST(cnt * duty_cycle, 100); + *space_cnt = cnt - *pulse_cnt; + + return *pulse_cnt >= 1 && *pulse_cnt <= 65536 && + *space_cnt >= 1 && *space_cnt <= 65536; +} + +static void meson_irtx_write_mod(struct meson_irtx *ir, unsigned int pulse_cnt, + unsigned int space_cnt) +{ + unsigned int cnt = pulse_cnt + space_cnt; dev_dbg(ir->dev, "F_mod = %uHz, T_mod = %luns, duty_cycle = %u%%\n", ir->carrier, NSEC_PER_SEC / ir->clk_rate * cnt, @@ -90,8 +103,10 @@ static void meson_irtx_set_mod(struct meson_irtx *ir) ir->reg_base + IRB_ADDR1); } -static void meson_irtx_setup(struct meson_irtx *ir, unsigned int clk_nr) +static int meson_irtx_setup(struct meson_irtx *ir, unsigned int clk_nr) { + unsigned int pulse_cnt, space_cnt; + /* * Disable the TX, set modulator clock tick and set initialize * output to be high. Set up carrier frequency and duty cycle. Then @@ -100,13 +115,18 @@ static void meson_irtx_setup(struct meson_irtx *ir, unsigned int clk_nr) */ writel(~IRB_ENABLE & (IRB_MOD_CLK(clk_nr) | IRB_INIT_HIGH), ir->reg_base + IRB_ADDR0); - meson_irtx_set_mod(ir); + if (!meson_irtx_calc_mod(ir->clk_rate, ir->carrier, ir->duty_cycle, + &pulse_cnt, &space_cnt)) + return -EINVAL; + meson_irtx_write_mod(ir, pulse_cnt, space_cnt); writel(readl(ir->reg_base + IRB_ADDR0) & ~IRB_INIT_HIGH, ir->reg_base + IRB_ADDR0); writel(IRB_FIFO_IRQ_ENABLE | MIRTX_FIFO_THD, ir->reg_base + IRB_ADDR3); writel(readl(ir->reg_base + IRB_ADDR0) | IRB_ENABLE, ir->reg_base + IRB_ADDR0); + + return 0; } static u32 meson_irtx_prepare_pulse(struct meson_irtx *ir, unsigned int time) @@ -215,12 +235,17 @@ static irqreturn_t meson_irtx_irqhandler(int irq, void *data) static int meson_irtx_set_carrier(struct rc_dev *rc, u32 carrier) { struct meson_irtx *ir = rc->priv; + unsigned int pulse_cnt, space_cnt; + + if (!carrier) + return -EINVAL; - if (carrier == 0) + if (!meson_irtx_calc_mod(ir->clk_rate, carrier, ir->duty_cycle, + &pulse_cnt, &space_cnt)) return -EINVAL; ir->carrier = carrier; - meson_irtx_set_mod(ir); + meson_irtx_write_mod(ir, pulse_cnt, space_cnt); return 0; } @@ -228,9 +253,14 @@ static int meson_irtx_set_carrier(struct rc_dev *rc, u32 carrier) static int meson_irtx_set_duty_cycle(struct rc_dev *rc, u32 duty_cycle) { struct meson_irtx *ir = rc->priv; + unsigned int pulse_cnt, space_cnt; + + if (!meson_irtx_calc_mod(ir->clk_rate, ir->carrier, duty_cycle, + &pulse_cnt, &space_cnt)) + return -EINVAL; ir->duty_cycle = duty_cycle; - meson_irtx_set_mod(ir); + meson_irtx_write_mod(ir, pulse_cnt, space_cnt); return 0; } @@ -337,7 +367,11 @@ static int meson_irtx_probe(struct platform_device *pdev) if (ret) return dev_err_probe(dev, ret, "modulator clock setup failed\n"); - meson_irtx_setup(ir, clk_nr); + ret = meson_irtx_setup(ir, clk_nr); + if (ret) + return dev_err_probe(dev, ret, + "carrier %u, duty_cycle %u%% not supported at clk_rate %luHz\n", + ir->carrier, ir->duty_cycle, ir->clk_rate); ret = devm_request_irq(dev, irq, meson_irtx_irqhandler, -- 2.55.0